Apparatus for locking cop tubes on cop winding machines



Oct. 20, 1953 BUNCH 2,656,127

. APPARATUS FOR LOCKING COP 'SI'UBES 0N COP WINDING MACHINE Filed June8, 1949 2 Sheets-Shget l 24 -4 22 FIG. 2

IN 5 N TOP r- 7. BU/ VCH A T TORNE V Oct. 20,1953 'r. T. BUNCH 2,656,127

- APPARATUS FOR LOCKING COP TUBES 0N COP WINDING MACHINES Filed June 8,1949 2 Sheets-Sheet 2 INVENTO R 7: 7. BUNCH BY FIG 6, ATTORNEY PatentedOct. 20, 1953 UNITED STATES PATENT OFFICE APPARATUS FOR LOOKING COPTUBES ON COP WINDING jMACHINES Tillman "r. Bunch, As'hland, Md.,assignor. to Western Electric Company, Incorporated, New York, N. Y., acorporation of New York Application June 8, 1949', Serial No. 97,832

9 Claims.

such as are employed in th manufacture of insulated electricalconductors or the like. The winding spindles of cop winding machines areprovided with variousmeans for holding the cop tube on the spindleduring the cop winding operation. It is desirable that the cop tubeholding means he a type which engages and disengages the cop tube with aminimum amount of effort and time in order to obtain a maximumproduction of cops from any given winding machine.

An object of the invention is to provide new and improved apparatus forlocking cop tubes on the winding spindles of cop winding machines.

Another object of the invention is to provide new and improved apparatusfor magnetically lockinga cop tube on the winding spindle of a copwinding machine.

,An apparatus embodying certain features of the invention comprises atubular spindle on which a tubular cop tube may be slidably positionedfor rotation with the spindle, and a magnetically-actuated means forholding the cop tube on the spindle while a cop is wound thereon.

A clear understanding of the inventio will be had from the followingdetailed description of a specific embodiment thereof, when read inconjunction with the appended drawings, in which:

Fig. 1 is a side elevation of a winding spindle embodying certainfeatures of the invention;

Fig. 2 is a section taken along lin 2-2 of Fig. 1;

Fig. 3 is a section taken along line 3-3 of Fig. 1;

Fig. 4 is a section taken along line 4-4 of Fig. 2, and showing themagnetic-locking means of the winding spindle in its cop windingposition;

Fig. 5 is a sectional view of the spindle similar to that shown in Fig.3 in which the magnet is shown in its actuated position and the cop andcop tube are shown in a partially released positoin with respect to thespindle, and

Fig. 6 is an enlarged fragmentary, sectional 2 view showing theright-hand end of the spindle shown in Fig. 3, and showing the keepingcircuit of the magnet positioned in the spindle.

Cop winding machines, in general, containone or more winding spindlesarranged to be driven a suitable manner and designed to receive a coptube on which a textile cop, or the like, is

wound to form a convenient supply package or cop to be used with servingand braiding machines. Since the general construction and operationofcop winding machines is known, only the construction andoperation of awinding feature embodying certain features of the present invention willbe described in detail.

Referring to Figs. 1 and 4 of the drawings, there "is shown a windingspindle comprising a shaft 10 suitably journalled in the frame of awinding machine, a portion of which is indicated by the numeral l I, andarranged to be driven by suitable means (not shown). A hub I5 is securedon the end of the shaft 10 extending beyond the frame I l, and hasoneend of an elongated tubular member 16, which is made of a magneticmaterial, rigidly secured on a right hand body portion 18 of the hub.The tubular member I6 is provided with four longitudinal grooves ll-Il(Figs. 2 and 6) spaced equally about the periphery of the tubularmember, that is, the grooves are positioned apart.

A ring 20 (Fig. 4) is secured to the periphery of an annular flange 2|provided on the hub l5 by :means of a plurality of set screws 22-22, theinner ends of which engage a conical groove 25 provided in the peripheryof the flange 2|. The ring 20 is countered-bored so as to form anannular shoulder 23 adjacent to the right end thereof, which shoulder isadapted to engage the upper edge of ribs 24-24 positioned between thebottom of the grooves ll-ll and the inner bore of the ring 20. japartabout the periphery of the ring 20 so as to be aligned radially with thegrooves 11-" and the ribs 24-24. The center of the conical groove 25provided in the periphery of the flange 2! of the hub 15 and the centerof th set screws 22-22 are misaligned so that when the set screws arethreaded into the ring, the conical end of the screws enters the grooveand draws the ring 20 to the left thereby causing the shoulder 23 toclamp the ribs tightly against the flange 2| of the hub 15.

A segment 26 (Figs. 2 and 4) is positioned between each pair of ribs24-24 (Fig. 2), and is arranged to slidably engage the periphery of theThe set screws 22-22 are spaced 90 tubular member IS and the internalbore of the ring 20. Each of the segments 26-26 is provided with ashoulder 21 adjacent to the right end thereof, which normally engagesthe shoulder 23 provided in the ring 20, whereby each segment 26 isretained within the ring Where it is subject to the action of a spring28 positioned in a bore 29 provided in the segment and a bore 30provided in the flange 2 I of the hub l5.

The free end of the tubular member it (Fig. 4) is designed to slidablyreceive an elongated cop tube indicated generally at 3| which iscomposed of two identical sections 32-32 (Fig. 6) of semicircularcross-section. Each section 32 is provided with an inwardly projectingrib 33 positioned centrally therein, and with inwardly projecting ribs tl-tt provided at the extremities thereof. When the two sections .3 2-732 are butted together and slid longitudinally onthe free end of thetubular member Hi, the inwardly projecting ribs 33-33 and 3i34 slidablyengage the grooves i'iil' provided in the tubular member and lock thecop tube thereon for rotation therewith. The internal bore of the coptube 3! is larger than the diameter of the tubular member it, and theinwardly projecting ribs 3333 and 3d3 l coact with the grooves ii-H toalign the cop tube concentrically on the tubular member so as to leavean annular clearance between the inner surface of the cop tube and theperiphery of the tubular member and between each rib 34% and the bottomof its adjacent groove. The purpose of maintaining an annular clearancebetween the internal bore of the cop tube and the periphery of thewinding spindle is to prevent the pressure imposed on the tube when acop, indicated generally by the numeral 35, is wound on the cop tubefrom causing the cop tube to bind on the tubular member !6.

There is provided within the tubular member 56 (Fig. 4) means formagnetically locking the cop tube ill on the spindle against alongitudinal movement while the cop 35 is wound thereon. The magneticlocking means comprises a sleeve 36 made of bronze or other suitablenon-magnetic material secured in the internal bore of the tubular memberit and a sleeve 37 made of bronze or other suitable non-magneticmaterial secured in the internal bore of the sleeve 56 ad jacent to theend of the hub 55. netic sleeves 35 and 3? have the same internaldiameters and are designed to slidably receive a cylindrical permanentmagnet dii having a cupshaped pole-piece 'secured on the right endthereof and a cup-shaped polepiece 42 secured on the left end thereof bymeans of a bolt d3 passing through a central bore 44 provided in themagnet ii] and threadedly engaged by a nut 56. A spring il positionedwithin the tubular mem-- ber it between the pole-piece 42 and the end ofthe hub i5 normally urges the permanent magnet 46 to the right so thatthe annular edge of the pole-piece d2 engages the end of the mommagnetic sleeve 3?, as shown in Fig. 4.

The permanent magnet Mi (Fig. i) is so ma netized that the magneticlines of force pass through it in a longitudinal direction as shown bythe dotted lines indicated by the numeral 50 (Fig. 3). The pole-piece 42is designed to slidably engage the internal surface of the tubularmember it, whereas the pole-piece GI is of such diameter that an annularair gap exists between the periphery thereof and the internal surface ofthe tubular member 16. The magnetic flux indicated by the dotted line53-40 The non-maginternal bore of the tubular serves to attract a ring52 made or" a para-magnetic material, and holds it tightly against theend of the tubular member it because the ring 52 is provided with aninternal bore 53, which slidably engages the pole piece 3!. The tubularmember i5 and the ring 52 are made of ferromagnetic material andtogether they form a closed ferromagnetic circuit for the magnetic fluxFit-5E! as shown in Fig. 4. The magnet 4%) produces a permanent magneticfield across the annular air gap 5|.

This arrangement provides a path for the magnetic flux of the magnet atfrom the pole-piece 4| through the ring 52 and the tubular member [6 tothe pole-piece :52, which has a reluctance substantially less than thereluctance of the annular air gap 5! between the pole-piece M and thetubular member E6. The member :5 is bevelled at 54 so as to reduce theannular contact area between the end of the tubular member l6 and theface of the ring 52 and thereby concentrate the lines of force of themagnetic circuit at the point of contact between the ring 52 and the endof the tubular member 53. The bevel 54 is designed to provide aconcentration of the flux at the point of contact which will cause themagnet to attract the ring with a predetermined force.

When the ring 52 is held against the end of the tubular member [6 by themagnet 49, as shown in Fig. l, the ring serves to hold the end of thecop tube 3i flush with the end of the tubular member Hi. The cop tube 3!is of such length that when the ring 52 holds it in such position, itmoves the segments 2626 to the left against the actions of theirrespective springs ZS-23, in which case, the spring-loaded segmentsserve to keep the cop tube pressed against the face of the ring and toprevent lateral movement of the cop tube on the spindle while the cop 35is wound thereon. This arrangement of the cop tube on the spindle makescertain that the cop 35 is wound centrally on the cop tube 3!. Theprovision of four grooves l'il'l on the tubular member. it permits thecop tube 3! to be positioned thereon in two positions, that is, thedividing line of the two sections of the tube may coincide with the lineA-A (Fig. 6) or with the line BB. The four segments was positioned inthe hub I5 are arranged so that two segments engage each half section ofthe tube 3i for either position of the tube on the tubular member 25.While the half -sections 32-32 may vary in length with respect to eachother, this arrangement of the segments 26-25 serves to maintain theright-hand end of each section against the ring 52.

The magnet 40 attracts the ring 52 to the end of the metallic tubularmember It so powerfully that it may not be removed readily from thetubular member with the magnet in a position shown in Fig. 1. To releasethe ring from the tubular member, it is necessary to push the nut 46 tothe left (Fig. 1) so as to move the permanent magnet 40 to the leftuntil the annular edge of the pole-piece 4i engages the ends of thesleeve 36, as shown in Fig. 5. When the permanent magnet has beenactuated in this manner, the pole-piece 4| is withdrawn from thecenterbore of the ring 52 so that the magnetic flux between thepole-pieces 4| and 42 does not pass through the ring 52, but passes onlyacross the air gap between the pole piece 4! and the member I6 andthrough the tubular member 16 as :indlc'ated by the dotted line 55. Byvirtue of the *air gap the external magnetic flux path 55 of the magnet4|] is discontinuous or open-circuited. When the pole-piece 4| has beenactuated to the position shown in Fig. 5, the ring is disengaged fromthe end of the tubular member I6 by theaction of the springs 28-28,which After the magnet 40 has been actuated in this manner to disengagethe ring from the "end of the tubular member It, the magnet is releasedand allowed to return to its position shown in Fig. 6, in which positionthe magnetic lines of force between the pole pieces 4| and 42 travelacross the annular air gap 5| and through the tubular member I6, asshown by the dotted line 56. The air gap 5| has sufficient reluctance tocause the magnetic flux of the magnet to pass through the ring 52 whenthe parts are positioned as shown in Fig. 3, but at the same timepermits the flux of the magnet to travel thereacross and complete themagnetic circuit and thereby retain the magnetism in the permanentmagnet when the ring 52 is not positioned against the end of the tubularmember l6.

Operation The above-described winding spindle operates in the followingmanner:

Let it be assumed that all the elements of the spindle are positioned asshown in Fig. 4., with the exception of the fact that the ring 52 is notin position, in which case, the path of the magnetic circuit between thepole pieces 4! and 42 is shown by the dotted line indicated by thenumeral 56. A cop tube of the type indicated by the numeral 3| is slidon the tubular member I 6 until it engages the spring-pressed segments26-26 and moves them to the left against the action of their respectivesprings 28-28. The right end of the cop tube 3| is positioned slightlyto the left of the right-hand end of the tubular member l6 and held inthis position until the ring 52 is positioned over the pole-piece 4| andmagnetically attracted to the end of the tubular -member l6 by themagnet 40 and the magnetic flux 50-50 (Fig. 3). When the ring is sopositioned, the cop tube may be released, in which case, the springs28-28 will move the segments to the right which segments in turn pushthe sections 32-32 of the cop tube to the right until the end thereofengages the face of the ring 52. Since two segments engage eachhalf-section 32 of the tube 3 the left end of each section is heldagainst the ring '52.

The spindle It then is rotated to wind a cop 35 on the cop tube 3|. Whenthe cop 35 is completed, the nut 46 is pressed so as to move thepermanent magnet 40 to the left against the action of the spring 41until the pole-piece 4| engages the adjacent end of the sleeve 36 asshown in Fig. 4. With the magnet 40 in this position, the external pathof the magnetic flux between the pole-pieces 4| and 42 is solely withinthe tubular member |5, as shown by the dotted lines 55-55 (Fig. 5). Whenthe pole piece 4| is withdrawn completely from the internal bore of thering 52 as described, the springs 28-23 push the segments to the rightuntil, they engage the shoulder 23 provided in thering 20 and impart asimilar longitudinal movement to the cop tube which disengages the ring52 from the end of the tubular member It as shown in Fig. 4. When thepermanent magnet 40 is released, the spring 41 urges it to the rightuntil the pole-piece 42 again engages the end of the sleeve 31, in whichcase, the magnetic circuit between the pole pieces lies solely withinthe tubular member It, as shown by the dotted lines 56-56 (Fig. 4) Whenthe ring 52 has been so removed from the end of the tubular member, thecop 35, including the cop tube 3|, may be removed readily from thewinding spindle.

The magnetically held ring 52 provides' a quick acting locking meanshaving a single part to be handled in locking a cop tube on a windingspindle of a winding machine and one which is designed to release thering quickly. These features of the magnetic lock facilitate easyinsertion of the cop tube on the winding spindle and quick release ofthe ring locking the cop on the spindle.

The permanent magnet 40 is made of a hard ,magnetizable material, whichhas the inherent property of retaining approximately a full con"centration of magnetic flux for a long period of time or evenpermanently. It also must possess the property of being capable of avery high induction of magnetic flux per unit area. of a given .sizemagnet. A material possessing these qualities is an alloy consisting ofabout 8% aluminum,

18% nickel, cobalt, 3% copper and the balance iron which is referred togenerally in the art as Alnico No. 5." When a cylindrical piece of thisalloy is 1 in diameter and five :inches long and having ferromagneticpole- .pieces Al and 42 secured on the ends thereof is fully magnetized,it will exert a total pull of approximately fifty pounds on the ring 52.This pull is more than sufiicient to compress the four springs 28-28 andto hold the cop tube 3| flush with the end of the tubular member l6while it is rotated to wind the cop 35 thereon.

The other properties of Alnico No. 5 are set Among other magneticmaterials which may be "used in making the permanent magnet 40 are thevarious Alnico alloys, Cunife (a copper, nickel,

iron alloy), and cobalt steel, which are described in the GeneralElectric catalog and the alloy composed of about 12 cobalt, Vo iron, and17% molybdenum.

The cop tube 3| is formed in two sections 32-32 in the manner describedin order that it tional cop tubes, such as the cop tube 3|, are

described more fully and claimed in my copend- ,ing application SerialNo. 97,831, filed June 8, 4949, for Strand Handling Apparatus. jto beunderstood that the cop tube 3| may be Qconstructed as a one-piece,tubular member havj- It is ing four internal ribs where it is to be usedwith eccentric type serving machines. Either type of jcop tube may beused readily on theftub ular member |6. r v

Obviously, the winding spindle" and the cop tubes used therewith neednot have only four coasting grooves and ribs, but, the number ofsuchgrooves and ribs may be varied as desired.

What is claimed is:

1. An apparatus for looking a cop tube on a cop winding machine, whichcomprises an elongated tubular spindle driven by such a machine andhaving a free end designed to slidably receive and rotate acop tube,yieldable means positioned at the opposite end of the spindle forengaging the end of the cop tube and urging it in a direction in whichthe cop tube is removed from the spindle, an elongated permanent magnetmounted resiliently within the tubular spindle so that one pole thereofnormally extends beyond the free end of the tubular spindle, said magnetbeing polarized so that its magnetic flux passes longitudinallytherethrough, said spindle forming an external path for the magneticfiux between the poles of the magnet, and an annular member ofparamagnetic material designed to be positioned slidably over the poleof the permanent magnet extending beyond the spindle so that it bridgesthe free end of the spindle and the adjacent pole of the permanentmagnet to complete a loW reluctance magnetic circuit which causes themember to be strongly attracted to the free end of the spindle, saidannular member being of such size that the outer portions thereof engagethe end of a cop tube positioned on the spindle and hold the cop tube onthe spindle against the action of the yieldable urging means, wherebywhen the permanent magnet is moved longitudinally with in the spindle tointerrupt the low reluctance magnetic circuit said yieldable meansslides the cop in a direction in which it is to be withdrawn from thespindle and disengages the annular member from the end of the spindle.

2. An apparatus for looking a cop tube on a cop in which the tube isremoved from the spindle,

a sleeve of non-metallic material secured within the tubular spindle, acylindrical permanent magnet positioned slidably within the non-magneticsleeve and polarized so that its magnetic flux passes longitudinallythrough the magnet, said magnet being designed so that one pole slidablyengages the spindle and the opposite pole extends beyond the free end ofthe spindle so as to form a permanent magnetic field between the freeend of the spindle and the pole of the magnet, and an annular member ofparamagnetic material positioned over the end of the magnet so as toengage the free end of the spindle and the cop tube and bridge themagnetic field between the magnet and the free end of the spindlewhereby the magnetic fiux holds the annular member tightly against theend of the spindle and thereby holds the cop tube on the spindle.

3. An apparatus for locking a cop tube on a cop winding machine, whichcomprises an elongated tubular spindle driven by such a machine andhaving its free end provided with a plurality of longitudinal groovesequally spaced about the periphery of the spindle, said. spindle beingdesigned to slidably receive a, tubular cop tube having inwardlyprojecting ribs which engage the longitudinal grooves and lock the coptube for rotation with the spindle, a plurality of springpressed stopspositioned slidably on the hub of the spindle for engaging one end ofthe cop tube positioned thereon, said spring-pressed stops beingdesigned to urge the cop tube in the direction in which it is removedfrom the spindle, a removable retaining ring designed to be fit againstthe free end of the spindle and having an annular portion extendingbeyond the periphery of the spindle to engage the end of the cop tube,means positioned in the spindle for causing a magnetic flux to passlongitudinally through the wall of the spindle and form a magnetic fieldat the free end of the spindle, said ring positioned against the end ofthe spindle bridges the magnetic field, whereby the magnetic fluxpowerfully attracts the ring to the end of the spindle and holds the coptube on the spindle against the action of the spring-loaded stops, andmeans for altering the external path of the magnetic flux so that themagnetic flux substantially does not pass through the ring whereby thering may be removed readily from the end of the spindle when it isdesired to remove the cop tube from the spindle.

i. An apparatus for looking a cop tube on a cop winding machine, whichcomprises an elongated tubular spindle secured for rotation by such amachine and having a free end portion provided with a plurality of'longitudinal grooves equally spaced about the periphery of the spindle,said spindle being designed to slidably receive on the free end thereofa cop tube having longitudinal projections engaging the grooves so as tolock the cop tube for rotation with the spindle, a plurality ofspring-pressed stops provided on the opposite end of the spindle forengaging one end of the cop tube and urging the cop tube in a directionin which it is removed from the spindle, a removable ring designed to befit against the end of the spindle and having portions extending beyondthe spindle to engage the end of the cop tube positioned on the spindle,and a cylindrical permanent magnet positioned slidably within thetubular spindle and having the portion intermediate the poles thereofmagnetically insulated from the tubular spindle, said permanent magnetbeing polarized so that its magnetic flux passes longitudinally throughthe magnet, said spindle forming an external magnetic circuit for theflux, said magnet normally forming a permanent magnetic field betweenthe free end of the spindle and the adjacent pole of the magnet, saidring bridges the magnetic field to complete a low reluctance magneticcircuit whereby said ring is attracted strongly to the free end of thespindle to hold flush the cop tube on the spindle against the action ofthe spring-pressed stops, said permanent magnet being slidablypositioned so that it may be selectively moved within the tubularspindle to interrupt the low reluctance magnetic circuit, whereby thering is removed from the end of the winding spindle by thespring-pressed stops.

5. An apparatus for looking a cop tube on a cop Winding machine, whichcomprises an elongated tubular spindle having one end secured to such amachine and its free end designed to slidably receive and rotate a coptube, means positioned at the inner end of the spindle for urging thecop tube in a direction in which the tube is removed from the. spindle,a sleeve of nonmetallic material rigidly secured within the tubularmember, a cylindrical permanent magnet slidably positioned within thenon-metallic sleeve and having a pole-piece secured on the inner'endthereof which slidably engages the internal surface of the tubularspindle (and a pole-piece mounted on the opposite end thereof and beinof such diameter that it forms an annular air gap between the pole-pieceand the inner surface of the spindle, a spring positioned between theinner end of the spindle and the first-mentioned pole-piece for normallypositioning the permanent magnet so that the second-mentioned pole-pieceextends a predetermined distance beyond the free end of the tubularspindle, an annular retaining ring of magnetic material designed to fitslidably over the second-mentioned polepiece and engage the free end ofthe spindle, said permanent magnet being polarized so that its magneticflux passes longitudinally through the magnet and longitudinally throughthe portion of the spindle positioned across the pole-pieces of themagnet and forms a permanent magnetic field across said air gap, saidring bridges the air gap between the free end of the spindle whereby themagnetic flux attracts the ring to the end of the spindle withsufficient force to hold a cop tube on the spindle against the action ofthe urging means, and means for moving the permanent magnet against theaction of the spring holding it in its normal position so that thesecond-mentioned pole-piece is withdrawn from the ring, whereby themagnetic flux is substantially diverted from the ring and said rin isdisengaged from the end of the spindle by the urging means.

6. An apparatus for locking a cop tube on a cop winding machine, whichcomprises an elongated tubular spindle of paramagnetic material drivenby such a machine and having a free end designed to slidably receive androtate a cop tube, a permanent bar magnet of relatively high mag- Um Inetic strength slidably mounted Within the tubular spindle and havingits inner pole in slidable contact with the inner surface of the spindleand its outer pole adjacent to the free end of the spindle, whereby amagnetic flux path is provided which includes the magnet, theparamagnetic spindle and an air gap between the free end of the spindleand the outer pole of the magnet, and a retaining member of paramagneticmaterial provided With a central aperture and designed to be slidablymounted on the outer pole of the magnet in engagement therewith and tocontact the free end of the spindle, thereby bridging the air gap andcompleting a magnetic circuit which causes the member to be attractedstrongly to the free end of the spindle, a portion of the retainingmember protruding beyond the outer periphery of the spindle to retain acop tube mounted thereupon.

7. An apparatus for locking a cop tube on a cop winding machine, whichcomprises an elongated tubular spindle of paramagnetic material drivenby such a machine and having a free end designed to slidably receive androtate a cop tube, resilient means mounted at the driven end of thespindle for urging the cop tube in a direction in which the tube isremoved from the spindle, a permanent bar magnet of relatively highmagnetic strength slidably mounted within the tubular spindle and havingits inner pole in slidable contact with the inner surface of the spindleand its outer pole adjacent to the free end of the spindle, whereby amagnetic flux path is provided which includes the magnet, theparamagnetic 'spindle'and an air gap between the free end of the spindleand the outer pole of the magnet, and a retaining member of paramagneticmaterial provided with a central aperture and designed to be slidablymounted on the outer pole of the magnet in engagement therewith and tocontact the free end of the spindle, thereby bridging the air gap andcompleting a magnetic circuit which causes the member to be attractedstrongly to the free end of the spindle, a portion of the retainingmember protruding beyond the outer periphery of the spindle to retain acop tube mounted thereupon.

8. An apparatus for looking a cop tube on a cop winding machine, whichcomprises an elongated tubular spindle of paramagnetic material drivenby such a machine and having a free end designed to slidably receive androtate a cop tube, resilient means positioned at the driven end of thespindle for engaging the adjacent end of the cop tube and urging it in adirection in which the cop tube is removed from the free end of thespindle, a sleeve of nonmagnetic material fixedly secured within thetubular spindle, a

, permanent bar magnet of relatively high magnetic strength slidablymounted within the nonmagnetic sleeve and having its inner pole inslidable contact with the inner surface of the spindle and its outerpole adjacent to the free end of the spindle, whereby a magnetic fluxpath is provided which includes the magnet, the paramagnetic spindle andan air gap between the free of the spindle and the outer pole of themagnet, and a retaining member of paramagnetic material provided with acentral aperture and designed to be slidably mounted on the outer poleor the magnet in engagement therewith and to contact the free end of thespindle, thereby bridging the air gap and completing a magnetic circuitwhich causes the member to be attracted strongly to the free end of thespindle, a portion of the retaining member protruding beyond the outerperiphery of the spindle to retain a cop tube mounted thereupon.

9. An apparatus for locking a cop tube on a cop winding machine, whichcomprises an elongated tubular spindle of paramagnetic material drivenby such a, machine and having a free end designed to slidably receiveand rotate a cop tube, a permanent bar magnet of relatively highmagnetic strength slidably mounted within the tubular spindle and havingits inner pole in slidable contact with the inner surface of thespindle, a spring which normally urges the magnet into a positionwherein the outer pole of the magnet is adjacent to the free end of thespindle with a small portion of the outer pole extending therebeyond, amagnetic flux path being provided which includes the magnet, theparamagnetic spindle and an air gap between the free end of the spindleand the outer pole of the magnet, and a retaining member of paramagneticmaterial provided With a central aperture and designed to be slidablymounted on the outer pole of the magnet in engagement therewith and tocontact the free end of the spindle, thereby bridg ing the air gap andcompleting a low reluctance magnetic circuit which causes the member tobe attracted strongly to the free end of the spindle, a portion of theretaining member protruding beyond the outer periphery of the spindle toretain a cop tube mounted thereupon, said cop tube being removable fromthe spindle by moving the magnet longitudinally from its normal positionagainst the action of the spring sufiiciently to inlease the retainingmeans.

TILIMAN T. BUNCH.

Bpfir nces Qitaq th fil? 9i th s mm UNITED STATES PATENTS Number1,236,965 1,261,356

Name Date M1 161 Au 1 19 Brown Apr. 2, 1918 Marquardt Mar. 31, 1925Martin June 7', 1927 Winslnw July 29, 1941 Number 2,260,055 2,309,9632,360,928 39,54 2,471,764 2.521 9 Number Name Date Reardqn Oct. 21, 1941li u eg 2-,--- e 2, 9 Bgeqhlyp Oct. 24, 1944 Plangti 1 Apr. 13, 1948Miller et a1. May 31, 1949 B1aj Oct. 24, 1950 FOREIGN PATENTS CountryDate Great Britain Mar. 27, 1936 G at Brita n May 27, 19.4

